Amazon Web Services Updated SAP-C02 Exam Questions and Answers by alya

To migrate an on-premises SFTP site to AWS with high availability and a set of static public IP addresses for external vendors, the best solution is to create an AWS Transfer Family server with an internet-facing VPC endpoint. Assigning Elastic IP addresses to each subnet and configuring the server to store files in an Amazon Elastic File System (EFS) that spans multiple Availability Zones ensures high availability and consistent access. This approach minimizes operational overhead by leveraging AWS managed services and eliminates the need to manage underlying infrastructure.

AWS Documentation on AWS Transfer Family and Amazon Elastic File System provides detailed instructions on setting up a highly available SFTP environment on AWS. This solution is in line with AWS best practices for migrating and modernizing applications with minimal disruption and ensuring high availability and security.

Enable DynamoDB Auto Scaling:

Navigate to the DynamoDB console and select the table experiencing high demand.

Go to the " Capacity " tab and enable auto scaling for both read and write capacity units. Auto scaling adjusts the provisioned throughput capacity automatically in response to actual traffic patterns, ensuring the table can handle the increased load.

Configure Auto Scaling Policies:

Set the minimum and maximum capacity units to define the range within which auto scaling can adjust the provisioned throughput.

Specify target utilization percentages for read and write operations, typically around 70%, to maintain a balance between performance and cost.

Monitor and Adjust:

Use Amazon CloudWatch to monitor the auto scaling activity and ensure it is effectively handling the increased demand.

Adjust the auto scaling settings if necessary to better match the traffic patterns and application requirements.

By enabling DynamoDB auto scaling, you ensure that the database can handle the fluctuating traffic volumes without manual intervention, improving response times and reducing errors.

References

AWS Compute Blog on Using API Gateway as a Proxy for DynamoDB【60】.

AWS Database Blog on DynamoDB Accelerator (DAX)【59】.

B is correct because the problem is caused by inconsistent query-string casing leading to CloudFront cache misses, and the best place to normalize the request is at the CloudFront edge before cache-key evaluation. CloudFront Functions run at the edge with very low latency and are intended for lightweight request manipulations (for example, normalizing URLs, headers, and query strings) on viewer request events. By sorting query parameters and converting them to lowercase on the viewer request, CloudFront will treat semantically equivalent requests as the same cache key, increasing cache hit ratio and reducing the number of origin calls to API Gateway and downstream Lambda invocations. This directly reduces latency for global users.

Why the other options are less suitable:

A (Lambda@Edge on origin request): Lambda@Edge can also modify requests, but it is heavier-weight than CloudFront Functions for simple normalization logic. Also, doing this on origin request occurs after CloudFront has already decided whether there is a cache hit. If the cache key is still based on the original mixed-case query string at the viewer side, you won’t consistently prevent cache misses. Normalization must happen before cache lookup to maximize cache hits.

C (API Gateway mapping templates): This normalizes the request only after it has already missed in CloudFront and reached the origin. It does not fix CloudFront cache fragmentation, so it does not meet the “minimal latency” goal as effectively.

D (Lambda authorizer): Lambda authorizers are for authorization/authentication decisions. Using an authorizer for query normalization adds unnecessary overhead and still happens at API Gateway (origin), not at CloudFront before cache evaluation.

GitHub Webhooks to Trigger CodePipeline:

Configure GitHub webhooks to trigger the AWS CodePipeline pipeline. This ensures that every code push to the repository automatically triggers the pipeline, initiating the build and deployment process.

Unit Testing with Jenkins and AWS CodeBuild:

Use Jenkins integrated with the AWS CodeBuild plugin to perform unit testing. Jenkins will manage the build process, and the results will be handled by CodeBuild.

Notifications for Bad Builds:

Configure Amazon SNS (Simple Notification Service) to send alerts for any failed builds. This keeps the engineering team informed of build issues immediately, allowing for quick resolutions.

Blue/Green Deployment with AWS CodeDeploy:

Utilize AWS CodeDeploy with a blue/green deployment strategy. This method reduces downtime and risk by running two identical production environments (blue and green). CodeDeploy shifts traffic between these environments, allowing you to test in the new environment (green) while the old environment (blue) remains live. If issues arise, you can quickly roll back to the previous environment.

This solution provides seamless, zero-downtime deployments, and the ability to quickly roll back changes if necessary, fulfilling the requirements of the startup company.

References

AWS DevOps Blog on Integrating Jenkins with AWS CodeBuild and CodeDeploy【32】.

Plain English Guide to AWS CodePipeline with GitHub【33】.

Jenkins Plugin for AWS CodePipeline【34】.